Board work machines such as solder printers, component mounters, reflow ovens, and board inspection machines are used to produce boards mounted with many components. These board work machines are often connected to each other to form a board production line. Among this equipment, component mounters provided with a board conveyance device, a component supply device, a component transfer device, and a control device are typical. A typical example of a component supply device is a feeder device that feeds tape in which many electronic components are stored at a specified pitch. Feeder devices are flat and thin in the width direction, and typically multiple feeder devices are arranged in a row on a base of the component mounter. Feeder devices have a motor in a mechanism that supplies components, and also a control section that controls operation of the motor.
Conventionally, contact-type electric power supply multi-terminal connectors are used for supplying electricity to the feeder device from the main body of the component mounter. However, with multi-terminal connectors, there is a problem of terminals being deformed or damaged due to repeated detachment and attachment. As a countermeasure to this, in recent years, the use of contactless electric power supply devices such as electromagnetic coupling type devices and electrostatic coupling type devices has progressed. Supply coils and receiver coils used in electromagnetic coupling type contactless electric power supply devices are each provided with a core, with a magnetic circuit being formed from the cores being arranged facing each other.
With an electromagnetic coupling type contactless electric power supply device, if the degree of coupling for the electromagnetic coupling lowers due to a gap arising between the cores, the ability to supply electricity is lowered. Thus, technology has been developed that controls changes in electric supply conditions while monitoring the size of the gap between the cores and the supply ability, an example of which is disclosed in patent literature 1. The contactless electric power supply device of patent literature 1 is provided with: an isolation transformer for which a supply side core and a receiver side core are separable and that includes a supplemental winding on the supply side core; and a mechanism recognizing section provided on the supply side core that mechanically recognizes information of the receiver side. Referring to claims 2 and 3 and an embodiment in patent literature 1, the mechanism recognizing section is configured to recognize the depth dimension of the receiver side plug so as to distinguish the type of load being received, and set the target voltage of the load side accordingly. Further, referring to claim 4, the detected voltage of the supplemental winding is taken as an indicator for performing control so as to supply a specified voltage to the load side.
The above mechanism recognizing section and supplemental winding are considered not to have a function that measures the size of the gap between the cores, and even if they were to possess such a measuring function, the measuring accuracy would be low. Conventional technology for measuring the size of a gap or the like, or the displacement of members is technology that uses light such as infrared or laser, or technology that uses magnetism or ultrasound. Technology that uses magnetism is appropriate for measuring proximity distances such as the size of the gap between cores, and an example of such technology is disclosed in patent literature 2. The distance measuring device of patent literature 2 is provided with a displacement sensor for which the inductance changes according to the distance to a measurement target object, an oscillation circuit that enables the frequency of the drive signal supplied to the displacement sensor to vary, a means for extracting the inductance of the displacement sensor based on changes to the frequency of the drive signal, and a means for measuring the distance to the measurement target object based on the extracted inductance. According to this, influences due to the resistance component and the capacity component of the displacement sensor are eliminated, and measurement is possible by only extracting the inductance component, which means that a highly precise distance measurement is achieved.